1. Field of the Invention
The present invention relates generally to a liquid crystal display device, and more particularly to a liquid crystal display device which prevents light leak between pixels.
2. Description of the Related Art
A liquid crystal display device, which is a representative one of flat-panel display devices, includes a liquid crystal display panel which is configured such that a liquid crystal layer is held between an array substrate and a counter-substrate which are attached to each other via a sealant. The liquid crystal display panel includes pixels which are arrayed in a matrix on a display area.
In this liquid crystal display panel, in some cases, light leak occurs between pixels. To cope with this problem, there is proposed a liquid crystal display panel including a light-blocking layer, i.e. a black matrix (BM), which is disposed in a lattice shape on the counter-substrate side in order to prevent light leak between pixels (Jpn. Pat. Appln. KOKAI Publication No. 2006-208530).
In the above-described structure in which the black matrix is disposed on the counter-substrate side, it is necessary to take into account misalignment between the array substrate and the counter-substrate, and light leak between pixels at a time of viewing in an oblique direction. In this structure, it is necessary to increase the width of the black matrix, and there may be a case in which a width of 10 μm or more is needed. Thus, there is such a problem that the ratio of an opening portion (“aperture ratio”), through which light from each pixel passes, decreases.
In particular, in recent years, a liquid crystal display panel which is mounted on, e.g. mobile phones, has an increasing demand for higher fineness and has a tendency that the pixel decreases. For example, in a liquid crystal display panel with 250 ppi (pixel per inch), the size of one dot (i.e. a set of an R pixel, a G pixel and a B pixel) is about 100 μm, and the size of a sub-pixel (e.g. an R pixel unit element) is about 30 μm, that is ⅓ of the size of the dot. In this high-fineness panel, a black matrix with a large width may become a major factor of a decrease in aperture ratio.